1KL7

Crystal Structure of Threonine Synthase from Yeast

Summary for 1KL7

• Entry DOI: 10.2210/pdb1kl7/pdb
• Descriptor: Threonine Synthase, PYRIDOXAL-5'-PHOSPHATE (3 entities in total)
• Functional Keywords: threonine synthesis, pyridoxal 5-phosphate, beta-family, monomer, lyase
• Biological source: Saccharomyces cerevisiae (baker's yeast)
• Total number of polymer chains: 2
• Total formula weight: 116228.75

Authors

Garrido-Franco, M.,Ehlert, S.,Messerschmidt, A.,Marinkovic, S.,Huber, R.,Laber, B.,Bourenkov, G.P.,Clausen, T. (deposition date: 2001-12-11, release date: 2002-04-24, Last modification date: 2025-03-26)

Primary citation

Garrido-Franco, M.,Ehlert, S.,Messerschmidt, A.,Marinkovic, S.,Huber, R.,Laber, B.,Bourenkov, G.P.,Clausen, T.
Structure and function of threonine synthase from yeast.
J.Biol.Chem., 277:12396-12405, 2002

PubMed Abstract: Threonine synthase catalyzes the final step of threonine biosynthesis, the pyridoxal 5'-phosphate (PLP)-dependent conversion of O-phosphohomoserine into threonine and inorganic phosphate. Threonine is an essential nutrient for mammals, and its biosynthetic machinery is restricted to bacteria, plants, and fungi; therefore, threonine synthase represents an interesting pharmaceutical target. The crystal structure of threonine synthase from Saccharomyces cerevisiae has been solved at 2.7 A resolution using multiwavelength anomalous diffraction. The structure reveals a monomer as active unit, which is subdivided into three distinct domains: a small N-terminal domain, a PLP-binding domain that covalently anchors the cofactor and a so-called large domain, which contains the main of the protein body. All three domains show the typical open alpha/beta architecture. The cofactor is bound at the interface of all three domains, buried deeply within a wide canyon that penetrates the whole molecule. Based on structural alignments with related enzymes, an enzyme-substrate complex was modeled into the active site of yeast threonine synthase, which revealed essentials for substrate binding and catalysis. Furthermore, the comparison with related enzymes of the beta-family of PLP-dependent enzymes indicated structural determinants of the oligomeric state and thus rationalized for the first time how a PLP enzyme acts in monomeric form.

PubMed: 11756443
DOI: 10.1074/jbc.M108734200

Experimental method

X-RAY DIFFRACTION (2.7 Å)